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[PATCH] i386 cpu hotplug: don't access freed memory

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i386 CPU init code accesses freed init memory when booting a newly-started
processor after CPU hotplug.  The cpu_devs array is searched to find the
vendor and it contains pointers to freed data.

Fix that by:

        1. Zeroing entries for freed vendor data after bootup.
        2. Changing Transmeta, NSC and UMC to all __init[data].
        3. Printing a warning (once only) and setting this_cpu
           to a safe default when the vendor is not found.

This does not change behavior for AMD systems.  They were broken already
but no error was reported.

Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Chuck Ebbert
2006-02-04 23:28:03 -08:00
committed by Linus Torvalds
parent 170aa3d026
commit fe38d8553c
9 changed files with 77 additions and 3 deletions
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11
arch/i386/kernel/cpu/common.c
View File

@@ -44,6 +44,7 @@ static void default_init(struct cpuinfo_x86 * c)
static struct cpu_dev default_cpu = {
.c_init = default_init,
.c_vendor = "Unknown",
};
static struct cpu_dev * this_cpu = &default_cpu;
@@ -150,6 +151,7 @@ static void __devinit get_cpu_vendor(struct cpuinfo_x86 *c, int early)
{
char *v = c->x86_vendor_id;
int i;
static int printed;
for (i = 0; i < X86_VENDOR_NUM; i++) {
if (cpu_devs[i]) {
@@ -159,10 +161,17 @@ static void __devinit get_cpu_vendor(struct cpuinfo_x86 *c, int early)
c->x86_vendor = i;
if (!early)
this_cpu = cpu_devs[i];
break;
return;
}
}
}
if (!printed) {
printed++;
printk(KERN_ERR "CPU: Vendor unknown, using generic init.\n");
printk(KERN_ERR "CPU: Your system may be unstable.\n");
}
c->x86_vendor = X86_VENDOR_UNKNOWN;
this_cpu = &default_cpu;
}